Demand valve



Feb. 3, 1970 J. T. cARuso 3,493,011

DEMAND VALVE Filed Hay 2, 196e,

INVENTOR. .)57222 I' Caras@ ATTORNEYS.

United States Patent O 3,493,011 DEMAND VALVE John T. Caruso, Kenmore,N.Y., assignor to Automatic Sprinkler Corporation of America, Cleveland,Ohio Filed May 2, 1966, Ser. No. 547,010 Int. Cl. F16k 17/34 U.S. Cl.IS7-484.2 4 Claims ABSTRACT F THE DISCLOSURE This invention relates tothe protective breathing field, and more specifically to a new anduseful valve arrangement in a pressure regulator for controlling thepassage of breathing fluid on demand.

It is important in apparatus of this type that the effort required to beexerted by the user be reduced to a minimum, as close to a normalbreathing effort as possible. It is also desirable to provide a highflow of breathing fluid immediately on demand, thereby satisfying thedemand for breathing fluid as rapidly as possible.

Accordingly, a primary object of this invention is to provide a demandvalve requiring a relatively low cracking force, providing a relativelyhigh flow of breathing fluid immediately upon being cracked open andwhich tends to assist the user in further opening the valve upon initialcracking thereof.

Another object of this invention is to accomplish the foregoing in arelatively simple, durable and dependable manner.

Breathing apparatus constructed in accordance with the instant inventionis characterized -by the provision of a demand valve having a generallysemi-circular orifice into a breathing chamber defined in part by aflexible diaphragm, a valve body engaging an orifice sealing surface andhaving a stem projecting into the chamber Ifor movement by the diaphragmin a plane, the orifice being generally symmetrical about that plane andpositioned generally between the stem and the diaphragm, and a flowdirector on the chamber side of the orifice, the director having a topwall positioned between the valve stem and the diaphragm and oppositeside walls defining with the top wall a generally U-shaped hood invertedrelative to the diaphragm and directed across the diaphragm to the fluidif outlet.

The foregoing and other advantages and characterizing features of thedemand regulator of this invention will become clearly apparent from theensuing detailed description of the illustrative embodiment thereofdepicted in the accompanying drawing wherein like reference numeralsdenote like parts throughout the various views and wherein:

FIG. 1 is a view partly in section and partly in side elevation, showinga demand regulator of this invention;

FIG. 2 is an end view of the fluid flow director thereof, taken about online 2-2 of FIG. 1 with all but the director and its attaching screwsomitted for greater clarity and ease of illustration;

FIG. 3 is a similar, opposite end View thereof, taken about on line 3 3of FIG. 1;

FIG. 4 is an end view of the valve seat disc, taken about on line 4 4 ofFIG. l and with all but the valve seat disc omitted `for greater clarityand ease of illustration; and

FIG. 5 is a similar, opposite end view thereof, taken about on line 5-5of FIG. 1.

Referring now in detail to the embodiment depicted by way ofillustration in the accompanying drawing, there is shown a regulatorhaving a hollow casing 1. A flexible diaphragm 2 is secured across theopen side of casing 1 to define a breathing chamber 3 therein. Diaphragm2 can be secured in place by any desired means, including for example alocking band 4, and has a reinforcing wear plate 5 engaging the outerend 6 of a tilt valve stem 7. A cover 8 is secured to casing 1, as byscrews, one of which is shown at 10, and provides a protective coverenclosing diaphragm 2. Casing 1 is provided with an inlet passage 11adapted Ifor connection to a source of breathing fluid under pressure,not shown, and an outlet 12 adapted for communication with the breathingmask of the user.

Thus, upon demand, that is, upon inspiration by the user the pressure inchamber 3 will be lowered relative to the ambient atmospheric pressureacting externally on diaphragm 2, thereby causing diaphragm 2 to moveinwardly of chamber 3, tilting valve stem 7 in the plane of the paper.

Fluid inlet 11 opens into an inlet chamber 13 connecting with breathingchamber 3 through a valve disc generally designated 14. Valve disc 14seats against a shoulder 15, with a sealing gasket 16 interposedtherebetween. Disc 14 is dished, inwardly of chamber 13, and has asemicircular kidney-shaped fluid orifice 17 therethrough. Orifice 17 issurrounded by a valve seat having a generally semi-circular portion 18substantially coincident with the curved outer circumference of orifice17. The valve seat is completed by a generally rectilinear portion 19extending crosswise of the opposite ends of orifice 17, between theopposite ends of the curvilinear seat portion 18.

The inner circumference of orifice 17 is defined by a tab 20 aperturedto loosely receive stern 7.

A circular valve body 21 is secured to stem 7 at its inner end, and hasa suitable sealing material surface 22 seating against the valve seat18, 19 in sealing engagement therewith. A helical spring 23 encirclesstern 7, seating at one end in an annular recess 24 in valve disc 14 andbearing at its opposite end against a stop 25 on stem 7. Spring 23 urgesvalve body 21 into sealing engagement against seat 18, 19, whereasmovement of diaphragm 2 into chamber 3 tilts stem 7 against therestoring action of spring 23 pivoting valve body 21 with its sealingsurface 22 centrally on the curvilinear seat portion 18. This opensorifice 17, admitting breathing fluid under pressure from inlet 11, 13into chamber 3. It is a particular feature of this invention that thefluid flow thus resulting from cracking upon valve 21 is directed andutilized in a manner assisting the user in further opening the valve.

To this end, there is provided a flow director 25 having a base 26seating on the inner wall surface of casing 1, around and against valvedisc 14. Director 25 is secured in position as by screws 27 extendinginto casing 1, thereby securing the director in position andsimultaneously holding valve disc 14 in mounted position.

Director 25 has an opening 28 therethrough, in general alignment withorifice 17, and is formed to provide a hood having a curved top Wallportion 29 and opposite side wall portions 30. The director hoodtherefore is of generally inverted U-shape, as viewed in FIG. 1, withtop wall 29 positioned between stem 7 and diaphragm 2. Stem 7 extendsbetween the hood side walls 30, outwardly beyond the hood, with top wall29 having a down turned outer end 31 terminating short of stem 7 in itscentered, rest position.

The axes of orifice 17 and director 25 are inclined upwardly towarddiaphragm 2, in the direction of fluid flow, and also toward outlet 12which is positioned lgenerally opposite inlet orifice 17. The director25 is positioned and anged to direct the incoming fiuid fiow acrossdiaragm 2 toward outlet 12. In other words, it ldoes not rely defiectincoming pressure fiuid from direct imlgement upon the diaphragm. Itdoes more than that, that it directs the fiuid flow relative to thediaphragm a manner tending to further increase the pressure differtialmoving diaphragm 2 into chamber 3. In other rds, the high velocity fiowof pressure fluid across tphragm 2 tends to further reduce the pressureactin-g :ernally against the diaphragm, thereby assisting in Jducingfurther inward movement of diaphragm 2 and rther opening of the valve21. In doing this, the genilly inverted U-shape of the director hood isimportant, cause it acts as a continuation of orifice 17, confining dshaping the incoming pressure fluid in a manner oducing the desiredresult. The desired alignment between orifice 17 and the rector hood isassured by a position lock 32 on valve sc 14 which is received in 'arecess 33 in the base of rector 25. The circular, symmetrical shape ofvalve body and its Sealing surface 22 avoids any need for preterminedangular orientation between the valve body ,d its seat. Having fullydisclosed and completely described my vention, what I claim as newis: 1. A breathing apparatus having a hollow casing with l opening inone wall thereof, a movable member selred across said opening to definean expansible chamber said casing, said casing having a fluid inletcommuni- ,ting with said chamber and adapted for connection to source ofbreathing fluid under pressure and a fluid outt communicating with saidchamber, means forming a :nerally semi-circular orifice between saidfluid inlet 1d said chamber at a position generally opposed to said lidoutlet across said chamber, valve means operably ;sociated with saidorifice for controlling the liow of reathing fiuid therethrough intosaid chamber, said tlve means including a valve body and a valve seatving an orifice sealing surface on the inlet end of said rifice remotefrom said chamber, said movable member :ing responsive to variations indifferential pressure ithin and without said chamber, a valve stemprojectlg from said valve body into said chamber for movelent by saidmember in a plane tilting said valve body on said valve seat to open thefluid passage through said orifice upon movement of said member intosaid chamber, said orifice being generally symmetrical about said planeand positioned generally between said stem and said member, and a fluidflow director on the chamber side of said orifice, said director havinga top wall positioned between said valve stem and said member ando-pposite side walls defining with said top wall a lgenerally U-shapedhood inverted relative to said member and directed thereacross to saidfluid outlet, said director and said orifice coacting in a mannertending to further increase the pressure differential moving said memberinto said chamber upon fiuid fiow through said orifice thereby assistingin further opening of said valve means.

2. A breathing apparat-us as set forth in claim 1, wherein said movablemember is a flexible diaphragm.

3. A breathing apparatus as set forth in claim 2, wherein said orificeand said flow director are inclined relative to said diaphragm in thedirection of said fluid outlet.

4. A breathing apparatus as set forth in claim 2, wherein said valveseat has a generally semi-circular portion aligned with said orifice andjoined at the opposite ends thereof by a generally fiat portionextending generally normal to said plane, said orifice being defined inpart by a tab bisected by said plane and extending generally from saidfiat seat portion toward the mid-point of said semi-circular seatportion, said tab being spaced from said semi-circular seat portion todefine the inner circumference of said orifice and being apertured toreceive said valve stem.

References Cited UNITED STATES PATENTS 3,095,890 7/1963 Cousteau et al.3,236,250 2/1966 Colombo. 3,357,447 12/1967 Zarichansky 137-4942,445,359 7 1948 Meidenbauer. t 3,145,721 8/1964 Miller.

WILLIAM F. ODEA, Primary Examiner RICHARD GERARD, Assistant ExaminerU.S. C1. X.R. 137--494

